1. Field of the Invention
The present invention relates to a video display apparatus which displays, e.g., monitor videos captured by monitoring cameras.
2. Description of the Related Art
Conventionally, monitoring systems are set up in commercial facilities such as hotels, office buildings, convenience stores, and financial institutions, as well as in public facilities such as dams, railroads, roads, and schools, for the purpose of deterring crime and preventing accidents. Such monitoring systems, for example, capture a monitoring area by a camera, transmit the video signal to a monitoring center such as a management office or security office, and display the video signal on a display. With this system, an operator can monitor the presence/absence of intruders by visually checking the display at the monitoring center.
When a plurality of cameras are used in this type of monitoring system, it is a common practice to sequentially switch the video signals of the plurality of cameras at predetermined intervals, and display the switched video signal on the display. In such display method, however, it is possible to display the video signal of only one of the plurality of cameras at one time. This may cause some important videos to be missed, and decrease the reliability of the monitoring operation.
For example, an apparatus which has a multi-screen display, and displays the video signals of a plurality of cameras on the plurality of screens at one time has been conventionally proposed (see, e.g., Jpn. Pat. Appln. KOKAI Publication No. 2002-152721). Such apparatus allows an operator to simultaneously monitor the video signals of the plurality of cameras while the video signals are arranged on the display.
In such conventional video display apparatus, however, the display screen must be divided into at least the number of screens which is obtained by multiplying the number of cameras with the number of events to be displayed, thereby complicating the process of arranging a plurality of screens. Since the size of each screen is small, performing the visual check is also difficult.